Figure 2.

(Top) Collaboration between ENL/AF9 and PcG. ENL/AF9 was reported to interact directly with SEC, DOT1L and PAFc and promote transcriptional elongation. ENL also interacts with PcG proteins, CBX8, RING1 and PCGF1, but the cellular function of the interaction remains unknown. We found that ENL interacts with the E3-ubiquitin ligase complex in Polycomb Repressive Complex 1 (PRC1), BMI1 and RING1B, and these work together to repress transcription under ATM-signaling. Therefore, ENL functions in both transcriptional elongation and repression depending on the circumstances. (Bottom) Collaboration of MLL-ENL/AF9 with PcG in Leukemia. PcG is involved in the tumorigenesis in MLL-ENL/AF9 rearranged Leukemia. “?” show the interaction, of which meaning is not clear or controversial.